Most of the things listed above do not really qualify as vigilantism. In my opinion vigilantism consists of playing judge jury and executioner. Executioner not necessarily being kill someone either. If you follow someone who just did a hit and run to get their plates, trip up some purse snatcher that is being a good citizen. But I think that this line can become blurred all to easily. There is a fine line between simply following someone and calling in their plates and pulling them from a car to beat their ***.

I do not see there being any real cause for concern regarding this in the near future. To many people are caught up in their own world to really notice any thing else.